Supplement Summary This application requests funds for the joint purchase, in partnership with NIGMS investigator Dr. Rajat Rohatgi, of an Olympus IX83 epifluorescence microscope. This instrument will help advance the goals of my NIGMS R01 award (R01 GM115968) by allowing us to study the fate of defective proteins which have escape Ribosome-associated Quality Control (Aim 2 of parent R01). The Olympus IX83 is a fully-motorized, automated inverted microscope system that includes laser-based autofocus (for high throughput imaging), a stage top incubator for environmental control, fluorescence recovery after photobleaching (FRAP) and iterative deconvolution capabilities. An instrument with these capabilities is not presently available on a cost-effective basis for either my research program or that of Dr. Rajat Rohatgi. The Biochemistry Department at Stanford will support this purchase with both funds for instrument service and space to house the microscope system. In summary, this microscope will accelerate the NIGMS-funded research projects in our laboratories and more broadly those of other NIGMS-funded investigators in the Department of Biochemistry at Stanford. ??